tickover issues

[dogbreath 0]

Hi, I have a standard 1.6 GTi 110k miles and a problem with idling. To stop the car  from cutting out whilst stationary, I have adjusted the small grub screw on (i think it is) the throttle body where the accelerator cable sits, but it idles when warm at 1500 revs. If I readjust it to idle at 1000 revs then it cuts out in stationary traffic. 

How can I get a reasonable idle and no cutting out?

Thanks, Steve.

[welshpug 1,661]

start by setting the screw back to where you had it originally check that the throttle switch is correctly adjusted and actually working, then leave it alone!

 

the screw you want to play with is the larger one which is an air bypass screw for the throttle, not the throttle itself.

[dogbreath 0]

should i set it to the 1500 idle when it is warm and alter the air ?

[welshpug 1,661]

no, they should idle more like 850-900 when warm.

[dogbreath 0]

Can you explain what I need to do? do I need to get it warmed up first ? Am a bit confused as to where I start. Do I drop the revs bu adjusting the small throttle screw or the big air screw? 

[DamirGTI 342]

Undo the small screw out and then back in till it barely touches the throttle leaver , then screw in 4 full turns and stop .. readjust the TP switch afterwards .

 

Do the similar with the allen screw on the AFM - screw fully in till it bottoms out , then unscrew 7-to-8 full turns and stop .

 

Start the engine , lights on , and adjust the idle speed via big brass screw on the TB as preferred (i like steady 1000rmp .. wait till it's fully warm to fine adjust the idle as it'll need to be higher when cold anyway)

 

This will get you pretty close and should work .. you might need just a little fine tune perhaps on the each said screw by smaller increments .

 

However , if it still idles bad .. and if the engine is mechanically good , good fuel mixture etc. ... then try to up the tension on the dizzy spring (scroll down for the pics) :

 

D

 

 

[dogbreath 0]

My idle today has been hideous. when warmed up the idle was oscillating from 600 revs up to 1600 and down every few seconds and finally cutting out, sometime later steady at 1200 then 1400.

What can be causing so variable an idle? Having to use the car as a daily commute and I can say it is the worst journey I have ever had. Cut out countless times, I was dreading slow moving traffic, kangarooing all down the road. Great when I put my foot down and get out of standing traffic. AAAARGH!

[welshpug 1,661]

sounds like you need a new afm and possibly a refurbished distributor, both of these transformed my 205, though they still need a large degree of finesse  (and good engine mounts!)  to drive smoothly.

[dogbreath 0]

luckily, i have a couple of spair air flow meters so i swapped one and reset the idle and (fingers crossed) behaved impeccably all day yesterday. got another dizzu so could have a go with that too if neccessary, but idle was a steady 1100 no wild variations. will keep it at that for a few days before i risk dropping it to 950 or so.

Thanks for all input. steve.

[dogbreath 0]

the car has been transformed. had 2 long journeys in start stop traffic today and behaved impeccably. amazing what a dodgy AFM can do!!!